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- mechanically Patented June Z), 1933 omrro s'mrcs PATENT OFFICE GEORGEL. BIDWEIIL, 0F BIEGELS'VILLE, PENNSYLVANIA, ASSIGNOB TO RIEGEL PAPERWEEQBATIQH, 0F BIEGEIISVHLE, NEW JERSEY, A CORPORATION OF JERSEY PAPERrelates to paper, and perticnlsrly paper, such as glsssine,imitapsrchment and the like, made from of gelstinized fibers; and theobject thsreoi is to improve the transparency, plishility, and otherdesirable characteristics in paper of type.

In, the manufacture of these papers in a standard Fourdrinierpaper-makingmachine,-

the paper stock is caused to ilow on the Fourdrinier wire where the webis iormed and a portion oi the water is extracted therefrom first bycapillary attraction as the web passes over tube rolls and then bysuction as it passes over the usual flat suction-boxes and the finalsuction couch roll. From the Fourdrinier wire the web is conducted, uponone or more, usually three, endless felt carriers, first between lowersuction and top press rolls snd'then between one or more pairs ofstandard press rollsby which more water is pressed from the web. Onleaving the last of these rolls the web passes over and around apreliminary pair of smoothing rolls and then over and around an extendedbattery of steam drying cylinders which serve to evaporate out most ofthe moisture contained therein. If the paper is to be sized a size'pressis at the end of the of cylinders and a few more drying cylinders areadded to remove some or all of the moisture taken up by the paper webfrom the size press, the number of the extra cylinders used dependingupon the grade of paper to be made. The paper 7 web or sheet thus driedis then passed through a pair of calendar rolls and wound up into rollsupon reels; and as each roll of paper is completed the reel is removedand setinbearingsonaframcandthepaperis' unreeled and run through aslitting and winding machine. Imitation parchment pa.- per is a finishedproduct at this stage, but, in the case of glassine, the paper requiresfurther treatment which consists in dampening it, by passing it througha mechanical dampener, then runningit through supercalcndarstogive it ahigh finish and partial ll transparency, and is usually waxed by run-Applicaticn filed Hay 10,1882. Serial No. 610,505.

sing it through a waxing machine to render it waterproof and still moretransparent.

I. have found that I can enhance the physi-v cal properties orcharacteristics of the paper by incorporating therein, during itsmenuiacture, small percentages of a mild alkali like sodiummeta-silicate, cerelose or its equivalent in grape sugar, glucose, ordextrose, or a combination of two or more of these materials, and aplasticizer like glycerglycol, magnesium chloride, or zinc chloride asby running the sheet when partially dried but while still holding aconsiderable percentage of moisture through a size-press containlng anaqueous solution of these materials. The cerelose or its equivalentimproves r the transparency, (glossy surface, silver whiteness,flatness, an grease-proof qualities of the paper, while the.:mild alkaliadds to the sheen and the] plasticizer serves,'when thus applied, togive the paper pliability and more or less stretch and in the case ofthe chloride of magnesium or zinc also adds to the weight of the sheet,and the degree of these characteristics in the finished paper can becontrolled by varying the percentages of the ingredients and by dilutingthe solution more 7 before it reaches and after it leaves the dryingcylinders. Such attempts, however, have proven ther unsatisfactory oruncommercial. For example, if the paper web is passed through thesolution when nearly dry it will take up very large quantities thereofand the excess will have to be dried out again. Decidedly the bestresults are obtained by dividing the battery of drying cylinders intotwo sections and installing between them a size-' press throughwhich'thesheet is run and subjected to a bath of the impregnatingsolution, preferably bringing the paper to the first section of dryerswith a moisture content of approximately 82 per cent. and so dividingthe battery that the cylinders in the first sec v The sheet willsubsequently lose all except approximately 5 per cent. of its moisturein passing through the second section of the drying battery, and thismoisture content will,

be increased to approximately 7 per cent. by subjecting its surfaces tothe action of a pair of cooling rolls before the sheet is reeled. Theordinary size press and extra drying cylinders, if used, should beinserted between the second section of the drying battery and thecooling rolls.

For the impregnating bath I now prefer, and recommend, cerelose as thematerlal for enhancing what may be termed the visual characteristics ofthe pa er, and glycerin as the plasticizcr to give it pliability andstretch, and highly satisfactory results have been obtained from usingin the size-press a solution composed, approximately, either of 20 percent. cerelose, 4 per cent. sodium meta-silicate,

20 per cent. glycerin, and 56 per cent. water or of 50 per cent.cerelose, 4 per cent. sodium meta-silicate, 20 per cent. glycerin, and26 per cent. water. A still more plastic sheet is obtained by the use ofa solution with .30 per cent. cerelose, 4 per cent. sodiummeta-silicate, 10 per cent. magnesium or zinc chloride, 20

per cent. glycerin, and 36 per cent. water,

while a very handsome sheet can be made with as simple a solution as 20per cent. cerelose, 20 per cent. glycerin, and 60 per cent. water.However, if very good plastic qualities are required, the heaviersolutions are more desirable. The sodium meta-silicate adds sheen to thesheet and hence it is desirable, although not essential, to use it inthe impregnating bath in the size-press as well as in the water withwhich glassine paper is later dampened as will now be explained.

I have also found that the transparency and glossiness or sheen ofsurface of glassine paper can be further enhanced by thoroughly andevenlydampening the sheet, preparatory to passing it through thesupercalenders, with alkali treated water-for example, water havingdissolved therein approximately 2 to 5 its equivalent, preferablydampening one side of the sheet both bypassing it through a mechanicaldampener and over an air-operated atomizer, then brushing the waterthoroughly over and intimately in contact with the fibers of the sheet,and then rolling the sheet into a tight roll. The paper when so treatedtakes on a very high gloss and becomes exceedingly transparent onpassing through the supercalenders, and it is further improved in theserespects when waxed and, especially, when run through a waxing machineusing a wax of a very high temperature.

It will, of course, be understood that the invention can be modified inits various details, within the scope of the appended claims, withoutdeparting from the spirit per cent. of sodium meta-silicate or b orsacrificing the substantial advantages thereof.

What I claim as' new, and desire to secure by Letters Patent, is v 1.Paper of the type described treated with an aqueous solution ofcerelose.

2. Paper of the type described treated with an aqueous solution ofcerelose and glycerin;

3rPaper of the type. described treated with an aqueous solutlon ofcerelose, sodium meta-silicate, and a plasticizer.

4. Paper of the t pe described having corporated therein before thedrying o the web has been completed a maternal like cerelose adapted toenhance its transparency.

5. Paper of the t pe described havin 1ncorporated therein before thedrying o the web has been completed a material like cerelose adapted toenhance its transparency and a plasticizer like glycerin.

6. Paper of the t pe described having corporated therein before thedrying o the web has been completed a materlal like cerelose adapted toenhance its transparency, a material like sodium meta-silicate adaptedto enhance its sheen, and a plasticizer.

7. Paper of the type described containing the materials incorporatedtherein by the treatment thereof before the drying of the sheet has beencompleted with a solution containing' approximately 20 to 50 r cent.cerelose, 20 to. 35 per cent. of a p asticizer, and 15 to 60 r cent. ofwater.

8. Paper of he type described containing the materials incorporatedtherein by the treatment thereof before the drying of the sheet has beencompleted with a solution containing approximately 20 to-40 per cent. ofcerelose, 2 to 5 per cent. of sodium meta-silicate, 15 to 35 per cent.of a plasticizer, and 20 to 63 per cent. of water. I

'9. lassine paper having incorporated therein a materia like cere oseadapted to enhance its transparency and a plasticizer like glycerin,'anddampened preparatory to eing supercalendered with water containing asmall per centage of an alkali like sodium meta-silicate.

10. Glassine paper having incorporated therein before the drying of itsweb has been completed a material like cerelose adapted to enhance itstransparency and a plasticizer, dampened preparatory to beingsupercalendered with water containing a small percentage of an alkalilike sodium meta-silicate, and waxed with a high temperature wax.

11. Glassine paper having incorporated therein before the drying of itsweb has been completed a material like cerelose adapted inv 12. Glassinepaper havingincorporated therein before the dryin of its web has beencompleted a material 11 e eerelose adapted toenhanee its transparencyand a plasticizer,

and waxed with a high temperature wax.

13. Glassine paper having incor orated therein from an aqueous solutionbe ore the drying of its web has been com leted with a material likecerelose, an alkali ike sodium meta-silicate, and a plasticizer, andwaxed with a high temperature wax.

14. Glassine paper having incor orated therein from an aqueous solutionbefore the drying of its web has beenrcompleted with materials likecerelose, sodium meta-silicate, and a plasticizer, dampened preparatoryto being supercalendered with water containing an alkali like sodiummeta-silicate, and waxed with a high temperature wax.

GEORGE L. BIDWELL.

